/**
 * Copyright (C) 2002-2015   The FreeCol Team
 * <p>
 * This file is part of FreeCol.
 * <p>
 * FreeCol is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 * <p>
 * FreeCol is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.sf.freecol.client.control;

import java.util.logging.Logger;

import net.sf.freecol.client.FreeColClient;
import net.sf.freecol.client.gui.GUI;
import net.sf.freecol.common.model.Game;
import net.sf.freecol.common.networking.Connection;
import net.sf.freecol.common.networking.MessageHandler;

import org.w3c.dom.Element;


/**
 * Provides common methods for input handlers.
 */
public abstract class InputHandler implements MessageHandler
{

    private static final Logger logger = Logger.getLogger( InputHandler.class.getName( ) );

    /** The main FreeCol client object. */
    private final FreeColClient freeColClient;


    /**
     * The constructor to use.
     *
     * @param freeColClient The <code>FreeColClient</code> for the game.
     */
    public InputHandler( FreeColClient freeColClient )
    {
        this.freeColClient = freeColClient;
    }


    /**
     * Gets the main freecol client object.
     *
     * @return The main freecol client object.
     */
    protected FreeColClient getFreeColClient( )
    {
        return freeColClient;
    }

    /**
     * Gets the GUI.
     *
     * @return The GUI.
     */
    protected GUI getGUI( )
    {
        return freeColClient.getGUI( );
    }

    /**
     * Gets the Game.
     *
     * @return The <code>Game</code>.
     */
    protected Game getGame( )
    {
        return freeColClient.getGame( );
    }

    /**
     * Deals with incoming messages that have just been received.
     *
     * @param connection The <code>Connection</code> the message was
     *     received on.
     * @param element The root <code>Element</code> of the message.
     * @return The reply.
     */
    @Override
    public abstract Element handle( Connection connection, Element element );


    // Useful handlers

    /**
     * Handles a "disconnect"-message.
     *
     * @param element The element (root element in a DOM-parsed XML tree) that
     *                holds all the information.
     * @return Null.
     */
    protected Element disconnect( Element element )
    {
        // Updating the GUI should always be done in the EDT:
        javax.swing.SwingUtilities.invokeLater( ( ) ->
                                                {
                                                    if ( getGUI( ).containsInGameComponents( ) )
                                                    {
                                                        if ( freeColClient.getFreeColServer( ) == null )
                                                        {
                                                            getGUI( ).returnToTitle( );
                                                        }
                                                        else
                                                        {
                                                            getGUI( ).removeInGameComponents( );
                                                        }
                                                    }
                                                } );

        return null;
    }

    /**
     * Handles a message of unknown type.
     *
     * @param element The element (root element in a DOM-parsed XML tree) that
     *                holds all the information.
     * @return Null.
     */
    protected Element unknown( Element element )
    {
        logger.warning( "Unknown message type: " + element.getTagName( ) );
        return null;
    }
}
